I have just endured the world’s newest longest flight, a 16,200km, non-stop ultramarathon from New York to Sydney. It took about 19 and a half hours, and was almost as demanding as that sounds.

The record-breaking Qantas Airways Ltd flight touched down early on Sunday morning in Australia. The Boeing Co Dreamliner delivered its few dozen passengers — including yours truly — to their destination more or less intact even if some of us were not quite sure what day it was.

Qantas wants to begin flying the time-saving route commercially as soon as 2022, so the airline used this test trip to explore ways to reduce its inevitable downside: A soul-crushing, body-buckling jet lag. Here is how my journey unfolded in real time.

Off the ground

Shortly after 9pm in New York, our plane has just left the John F Kennedy International Airport and it has already become a flying laboratory. Since the goal is to adapt to our destination’s time zone as fast as possible, we click into the Sydney clock right off the bat. That means no snoozing. The lights stay up and we are under instructions to stay awake for at least six hours until it is evening in Australia.

This immediately causes trouble for some passengers.

Down one side of the business-class section, six Qantas frequent flyers are following a pre-planned schedule for eating and drinking (including limiting alcohol intake), exercising and sleeping. They wear movement and light readers on their wrists, and have been asked to log their activities; they have already been under observation for a few days and will be monitored for 21 days in total. Most of them are bingeing on movies or reading books, but one of them is dozing within minutes. To be fair, I feel his pain. It may be the middle of the day in Sydney, but my body is telling me it is pushing midnight back in New York.

Two hours in

It is feeding time, a key moment in the experiment. The specially designed dishes are supposed to fire me up, and a flavourful serving of poached prawns with chilli and lime is like a gentle culinary slap on the face. Spicy Chinese-style cod with jasmine rice and sesame seeds repeats the explosive action. I am momentarily awake.

The plane’s 40 passengers, including the media, are all in the business class: With so few passengers, nobody needs to travel economy. In an interview, Qantas chief executive officer Alan Joyce tells me the real Project Sunrise flights — if they go ahead — will have more legroom in the economy class than standard planes and there will be some space at the back of the aircraft for stretching.

The six human guinea pigs at the heart of the research are seated on one side of the cabin. I want to do my own set of tests to see how my body is holding up.

After speaking to a travel doctor in Sydney before the trip, I am armed with equipment to monitor my blood pressure, heart rate and oxygen saturation levels. I have also got a memory test and a mood questionnaire. I want to see if a flight this long impairs my brain or dims my spirits.

The three-hourly tests I take during the first half of the flight reflect the demands of this trip. My blood pressure is elevated, though not high, and my heart rate picks up. My mood is light, though darkening very gradually.

Three hours in

The physical pressure of this experiment is clear. Around me, passengers are standing up just to stay awake. The crew have been asked to keep sleep diaries, and to use iPads to rate their fatigue, reaction times, workload and stress. That dozy frequent flyer at the front of the plane is asleep again.

While I find this regime fairly challenging — and I am not even in a do-it-tough economy seat — I try to keep things in perspective. After I first wrote about this upcoming flight last week, one reader emailed to urge me into a stouter mindset. During the Korean War in the early 1950s, he said, he regularly flew 40-hour reconnaissance missions with crew rotations every six hours. “Man up,” the 83-year-old told me. Point taken.

Four hours in

Marie Carroll, a professor at the University of Sydney who is overseeing the passenger research on the flight, rallies her troops at the back of the plane. “This is the time, guys, when we really have to work through this,” she tells them. Moments later, they are leaning against the food trolleys in the galley, stretching. Next, they perform upright press-ups among the empty economy sets. As a finale, they attempt synchronised dance moves in the aisles — all in the name of science.

It looks like cabaret, but beating the jet lag is serious business. Beyond the sleepless nights and daytime fatigue, experts say critical processes including heart function and metabolism are upset when the body clock gets disrupted.

Seven hours in

A second meal arrives. For me, being fed twice in a relatively quick succession has really helped time pass quickly during the first part of the flight. This part of the menu should mean the next few hours slip by too: It is heavy on carbohydrates and designed to send us to sleep. The sweet potato soup with creme fraiche is thick and luxurious, while the toasted cheese sandwich is less so. The chef on the plane tells me he has been preparing our meals for three days.

The lights are dimmed at last and it feels like I have been released. I crash for six hours straight. That is longer than I can remember sleeping without waking on any other flight even with the business-class privilege of a flat bed.

Fourteen hours In

Across the board, my own medical tests suggests that I am coping. My blood pressure, which the doctor in Sydney said would be a good gauge of stress and fatigue, is back to normal. My heart is pumping slower, I ace my memory test and my questionnaire shows my mood is brighter.

The research on the passengers and the crew will feed into Project Sunrise, Qantas’ plan to start direct commercial services connecting Sydney with New York and London. Other super-long flights from Australia’s eastern seaboard to South America and Africa might follow, Qantas says.

On board, Joyce tells me he will “absolutely” roll out this flight’s regime on his other long routes — if the science shows it helps. The trick is accommodating those who want to drink and snooze at will, Joyce says.

But do not go booking your round-the-world flights just yet. Qantas needs new planes from Boeing or Airbus SE that can do the job with a full load of passengers, and a new deal with the crew to work longer than 20 hours. “It needs everything to come together,” Joyce says. He initially had dreams of turning these super-long flights into flying hotels with sleeping berths or a workout zone. That vision gave way to reality when profit margins proved too tight to waste space on such luxuries.

Our plane does not have the range to haul a full load of passengers with luggage to Sydney. It took off with its fuel tanks maxed out — about 101 tonnes. To keep the weight down, there is no cargo, and food and drinks are limited. In New York, the captain had seemed confident we would make it to Sydney with gas to spare. He planned on landing with six tonnes of fuel, enough to stay airborne for another 90 minutes.

Seventeen hours in

It is breakfast time and there is no limp sausage. Instead, it is a bowl of ancient grains, avocado puree, warm halloumi cheese and a herb salad. This flight is turning everything on its head.

One of the frequent flyers, Sydney-based investor Nick Mole, says he got almost eight hours of sleep and feels good. What about a full day’s work after landing? “I probably could do that,” he says. He thinks the bigger test will be how he copes in a couple of days.

Preparing to land

I feel better now than I did after flying to New York from Sydney a few days ago with one stop. The dozen or so hours it took to reach Los Angeles were followed by a grating hour and a half queuing at immigration with hundreds of other zombified travellers.

As our plane approaches its destination, Joyce addresses everybody on board. He tells us the flight has given him more confidence that Project Sunrise can work. And come Sunday lunchtime in Sydney, I am feeling jaded but far from debilitated. I even made it through a children’s birthday party, surely an acid test of anyone’s nerves.  

Personally, I would choose a direct Sydney-New York flight over one with a lay-over. But it would not suit everyone: It took discipline and work to stick to the no-sleep routine in the first half of this flight. There may be a benefit to switching to the destination time immediately but it comes at a price. I feel like I had to earn it. — Bloomberg